''The X-Files: I Want to Believe'' is the second feature film based on ''Series/TheXFiles'', released in 2008 (a full ten years after [[Film/TheXFilesFightTheFuture the first]]).

It features series protagonists Fox Mulder and Dana Scully long after they abandoned the FBI and the X-Files; Scully is a doctor at a Catholic hospital concerned about the treatment options offered to a dying boy, and Mulder, still on the lam, lives as a hermit under Scully's protection, doing little more than collecting paper clippings. They are offered a chance at redemption, however, when the FBI requests their help in finding an old comrade, who has herself gone missing while investigating a series of mysterious disappearances. They are aided by an ex-priest and [[PedophilePriest convicted pedophile]] named Father Joe, who claims to receive psychic visions of the victims directly from {{God}}, and about whom the agents have conflicting feelings.

The film is a stand-alone work in the tradition of the show's MonsterOfTheWeek episodes, and does not revisit the series' famous -- and still unresolved -- MythArc.

!!''The X-Files: I Want to Believe'' provides examples of:

* AbortedArc: Scully and Mulder both appear to be completely unconcerned about the supposedly inevitable [[spoiler:extraterrestrial colonization of Earth coming in four years]]. It's not even ''mentioned''.
* BeardOfSorrow: Mulder's grown one.
* BlackSpeech: The deadly medical staff speak Russian and Czech in a post-Cold War East-West paranoia way.
* BlatantLies:
-->'''[[spoiler:Skinner]]:''' It's Mulder. He wouldn't do anything crazy.
* ContinuityNod: Several little ones.
* DarkerAndEdgier: Than most of the TV series -- in tone as well as lighting.
* DeadlyDoctor: Deadly doctors and nurses.
* DeathEqualsRedemption: [[spoiler:Father Joe wants to do some good before he dies.]]
* DistressedDude: Scully had the DistressBall in the first movie, so it's Mulder's turn now.
* GondorCallsForAid: [[spoiler:Skinner]] makes a surprise appearance in this role.
* HiddenInPlainSight: Mulder's in hiding from a death sentence. Surely no-one will ever think to look for him at Scully's house! {{Handwave}}d by the suggestion that the FBI is just glad to have him out of their hair, although given ''why'' he's under a death sentence that doesn't really explain much.
%%* IrishPriest: Father Joe
* LastNameBasis: Despite the obvious RelationshipUpgrade, you won't hear Mulder or Scully call each other "Dana" or "Fox" even once.
%%* LittlestCancerPatient: Christian
%%* LosingYourHead
* MeaningfulName: The LittlestCancerPatient causing a schism in Scully's faith in God and her faith in science is named ''Christian''? Really?
* MortalityPhobia: The plot of this movie concerns a Russian who doesn't want to die, so he has his medial {{mooks}} [[spoiler:kill people and graft his head onto their bodies]] so he can live a little bit longer. They've done this several times before the start of the film and a couple more times during the film before they're stopped in the end. It appears they're just doing it ForScience, they don't especially care about the guy or payment.
* PedophilePriest: Father Joe
* NeverTrustATrailer
** Despite rumor and the domestic trailer portraying the movie (correctly) as an upgraded MonsterOfTheWeek, the international trailer went out of its way to make it look like a movie about aliens.
** One trailer implied that Mulder and Scully had gone their separate ways after the end of the series and were reuniting, much to the outrage of fans. Luckily, that's disproven within the first few minutes of the movie.
* RefusalOfTheCall
-->'''Scully:''' I'm done chasing monsters in the dark.
* RelationshipReveal: Mulder and Scully. (It was strongly implied that they'd gotten together in the last few years of the show, but it took until this movie for the writers to ''finally'' stop trying to be coy about it.)
* SecondActBreakup: [[spoiler:It does seem to be fixed by the end, though.]]
* ShoutOut: See the [[ShoutOut/TheXFiles sub-page]] listing Shout Outs from the whole franchise.
%%* SnowMeansDeath
* SurgeonsCanDoAutopsiesIfTheyWant: Scully, a forensic pathologist during the show, is now working in the field of pediatric neurosurgery. Although enough time has passed that she might have returned to school or something, it's not explained or even alluded to.
* TearsOfBlood: Happens to Father Joe during his psychic visions.
* ViolentlyProtectiveGirlfriend: Scully [[spoiler:knocks a man unconscious with a piece of firewood to stop him from killing Mulder]].
* WhatHappenedToTheMouse: No information is given on the whereabouts of Doggett and Reyes.